Preamble

In 2013, in response to repeated requests,
Zooko and I collaborated on a brief guide to getting started on a ketogenic diet.
As the primary author and research lead on the
Ketogenic Diet for Health website,
I had shied away from giving dietary advice,
preferring to share only my interpretations of the scientific literature.
In fact, I was so averse to the idea of telling people what to eat,
that Zooko penned it essentially single-handedly,
while I provided only a few edits, and the title, which I have kept here.
I further insisted it not be hosted on that site,
which I felt ought to contain only discussion of scientific literature.
I am grateful for his willingness to write that piece,
because I know his work has helped many people.

I had already been eating a carnivorous diet for four years at that point,
and knew that a carnivorous diet appears to work for many people for whom a regular,
garden variety, keto diet isn't enough.
In my experience, it is easier to start with a more restricted diet,
and if that is successful, to carefully expand the repertoire as tolerated and desired.
That way, if problems occur, you always have the option to go back to what worked,
while figuring out what to do next.
And so, in the tradition of many great low carb authors,
(as discussed in this follow-up)
our recommendation was not to begin with
the kind of low carb diet that many long term keto dieters eventually settle into eating.
What we said was:

"Our recommendation is simple: eat nothing but meat for 30 days."

(Note that by meat, we mean animal sourced foods, not necessarily only steak, though that is an option.)

Indeed, the rest of the article is mostly just affirmation that you read that correctly,
a few clarifications, and some pitfalls to avoid.
It also contained some general advice pertaining to ketogenic diets.

Because this keto starting guide recommended a completely carnivorous diet,
and was one of the first sites that did so,
it has become a reference for people beginning a so-called "zero-carb/ZC" diet.
As such, it deserved an update more specifically for that.
If you are looking for our previous version,
which is geared toward using a carnivorous diet to kickstart a ketogenic diet
for those new to ketogenic diets,
it can now be found here.
If you are already familiar with or following a ketogenic diet,
and are looking to transition to a carnivorous diet, continue on this page.

Important note: If you are on a prescription drug

A ketogenic diet has a powerful effect on the body and starting one could very rapidly change the effective doses of certain medications.
For example, drugs that affect blood pressure or blood sugar could suddenly be in dangerous excess.
If you are on a potent drug, it is advisable to get help monitoring your situation while transitioning to a ketogenic diet.

Why would I do this?

We have little to no clinical evidence of benefit from plant free diets [1],
and plenty of evidence of benefit from ketogenic diets,
so why would anyone already on a ketogenic diet willingly restrict further an already restricted diet?

The answer is that the number and types of anecdotes of clear and significant benefit is too large to ignore.
Not only are many people finding impressive positive benefits from a shift to a plant-free diet,
but many are experiencing remission of diseases considered progressive and uncurable.
Moreover, a carnivorous diet is safe to try. This makes the risk to reward ratio extremely favourable.
You might want to try a carnivorous diet if:

The only clinic I know of that uses and advocates a meat only diet, is Paleomedicina in Hungary, under the direction of neurobiologist Zsófia Clemens.

How do I start?

I recommend you dive straight in to carnivory cold turkey (or hot beef).
If you are going to get benefits, you might as well find out right away.
Ultimately, it will save time and agony, and give you more information.
Get as many confounds out of the way as you can.
The faster you can determine if carnivory is right for you,
the faster you can get the benefits and get on with the rest of your life.
There are far more interesting things to focus on than what you are having for dinner.
One of the great beauties of carnivory is that the process of eating becomes so simple,
it opens up time to think about other things.

Carnivory is not typically difficult.
What difficulties there are are primarily psychological and social.
So you need to commit and prepare.
Commit by knowing why you want to try it.
That's what will get you through.
Don't do it if you're not really sure,
because breaking your word to yourself is damaging to self-esteem.
For this reason, it helps to make it a short-term commitment;
if you end up feeling doubtful you know you can stick to it, because it will be over soon.
Prepare by ridding your environment of foods you know are tempting.
Have some meals planned and shop ahead.
Know what social situations will be scheduled and have a plan for how to respond to tricky ones.
More on that below.

Some people like to have a partner in on their plans,
for accountability purposes.
If you have someone you trust deeply, and that appeals to you, go for it.
I am usually in the school of keeping goals private,
especially if what you are doing is in any way controversial.
First of all, you don't want to have to deal with other people's "concern."
Tell people you want to try jumping from an airplane and they'll nod approvingly.
Tell them you want to avoid eating plants for a month,
and they're likely to flip out and try to talk you out of it, or at least demand you defend your choices.
When I stopped eating plants, the last thing I wanted to do was tell my friends about it.
It's just not the way I roll.
I'd rather pull it out of my pocket after I've been doing it awhile—
"Oh, by the way..."
(I admit that may be a personality quirk.
There's a lot people don't know about me right off the bat, and that's how I like it.)
Second, I am very uncomfortable when other people ask me how something is going during difficult moments.
If I'm struggling with a commitment, it only feels worse to think someone else is invested in it, too.
Worse, they might try to solve my problem for me.
I like to solve things on my own.
Nonetheless, I recognise that many people do better with social support.
Internet forums can be very helpful.
Even this introvert used them extensively in the beginning.
If you already know what style of experimenter you are, stick with that.

How long do I have to do this to know if it's of benefit?

As before, I recommend a 30-day trial.
In truth, there are some people who don't start to see the benefits until more time has passed.
Other carnivory experts recommend a much longer experiment,
and have noted that many do not fully adapt to the diet until about 6 months.
I do not at all dispute this observation.
I simply think that a 6 month commitment is too much to ask of most people.
If you are very sick and at your wits end for a solution,
you may be willing to give it 6 months,
but if you are just curious,
just slightly dissatisfied with the status quo,
6 months may seem too intimidating, too big a sacrifice.

Many people experience clear benefits essentially immediately,
within a couple of days or a week.
After 30 days, many will already have experienced
a consistent health improvement from a plant free diet,
and they will have gotten through the psychological adjustments necessary to
make it practical and sustainable, should they wish to continue.
After 30 days, most people are in a good position to know
what it takes to implement it, and whether it is worth it.
The idea of eating only meat can be extremely intimidating.
After 30 days, it is evident how surprisingly easy it is.

What should I actually eat?

Invariably people want to know what to eat,
and often ask for recipes.
I usually deflect this latter question.
The thing is, recipes, in the traditional sense
are almost the antithesis of carnivorous eating.
Keto needs recipes, because people are trying to make food seem like what it was before keto.
They mock up things like pancakes, cookies, pasta, rice.
Don't get me wrong.
I spent over a decade on a low carb diet before I started eating this way
and I've made all manner of low carb desserts and comfort foods.
It's fun. Some of the recipes out there are ingenious, and delicious.
No one on a ketogenic diet need ever miss the way they used to eat.
This kind of intervention can get you through when you're feeling deprived,
and can make the difference between success and failure.
For this experiment, though, you're going to take a different approach.

To habituate yourself to a carnivorous diet
it's best to forget about trying to imitate other kinds of food.
Meat doesn't need to mask itself to taste fantastic anyway.
It's not as though we're dealing with tofu.
What carnivorous eating asks for is not recipes, but kitchen skills.
In my book I will provide as many tips as I can gather for bringing out the best in meat.
Here, I'm only going to to tell you what to eat, not how to cook it.

In my experience, people have the best response when they:

Focus on "whole" cuts of fresh meat, preferably cooked at home.

Stick primarily to fatty cuts. My list below includes some lean choices. If you use them a lot, you may want to supplement butter, tallow, lard, or fish oil. For this trial, do not use vegetable oils, not even coconut oil. Many people are intolerant of it.

Avoid seasoning or sauces of any kind, with the possible exception of salt (see the FAQ below).

Minimise "processed" meats.

Do not let themselves get hungry. Eat as often as you like until you are full. Err on the side of full. You aren't trying to fool your body, you are trying to feed it.

Staples include the following examples.
These reflect my cultural biases living in the U.S.A.
Other countries cut differently and have different preferences.

Beef

Steaks such as ribeye, sirloin, strip, and chuck eye

Short ribs

Roasts such as prime rib, chuck, brisket

Ground beef or strips of beef for stir-fries

Organs such as liver, heart, and sweetbreads

Marrow bones

Lamb

Ribs

Chops

Shank

Pork

Shoulder or butt roasts

Baby back ribs, spare ribs

Shoulder chops

Pork belly

Poultry

Wings

Thighs and drumsticks

Breast is typically too lean, except for goose and duck.

Fish and shellfish

Salmon

Trout

Mackerel

Sardines

Oysters

Mussels

Crab

Lobster

Shrimp

Scallops

Eggs

Chicken

Duck

Roe

Heavy cream

Some people are sensitive to dairy, so this is a maybe.
More below.

Stocks and broth from bones and scraps make excellent hot drinks.

Frequently asked questions

...

Should I measure ketosis?

No. You will probably be in ketosis, but probably only mildly to moderately so. It doesn't seem to matter much in most of those who derive benefit, and it tends to drive obsessive behaviour that prevents eating to satiety.
Unless you have some overriding need to manage your ketosis levels directly,
I would defer that until and unless you need to troubleshoot, or just want to experiment further later.

Can I drink coffee?

This is a tough call. Coffee is a plant extract, but it's also a drug.
If you are a habitual coffee drinker, adding quitting coffee to the experiment will make it difficult.
It's not an ideal time.
Because I've personally not experienced additional benefit to quitting coffee,
in any short term experiment,
I'm biased toward leaving it in if that's your preference.
However, I do think it is worth a trial without either now or later.
For some people it could make all the difference.

Can I drink alcohol?

I would advise skipping alcohol entirely for the duration of the experiment.
If that's a difficulty for you, you might want to reflect on that.

What should I drink, then?

Water, with or without carbonation or minerals, to thirst.
Broth makes a nice warm drink on a cold day.

Can I eat dairy?

Many people are sensitive to dairy. It makes sense to leave off dairy at least for the first couple of weeks,
especially cheese and yogurt, which are notorious for causing weight gain at innocent calorie levels, and addictive behaviour.

What's the deal with processed meat and can I eat bacon?

I recommend against eating processed meats, for the following reasons.
Many processed meats contain additives that cause reactions in sensitive people.
Moreover, aged meats are high in histamines, which many people are sensitive to.
Please see Dr. Georgia Ede's website for more information on histamine sensitivity, and a wealth of other information on plants, meat, and nutrition.
These are confounds we don't want to deal with right now.

I hesitate to suggest avoiding bacon.
Many people do fine with it, and it's a perennial favourite.
Because you may have sensitivities to additives or to histamines (or for that matter, pork),
I would suggest going a week or two without it, if your results haven't been what you hoped.

You could also try fresh pork side. My grocer sells it frozen.
It is the same cut and form factor as bacon, without the curing.
You can salt it as desired and you may find it hits the spot.
I actually prefer it.

Do I need to avoid salt?

There is no good reason I know of to avoid salt.
It does not materially affect blood pressure, and there is no evidence it is unhealthy in amounts to taste.

Do I need to add salt?

You may have heard recommendations to actually increase salt during a ketogenic diet.
This is likely to be helpful during keto-adaptation, and periods of intense exercise.
Some people seem to benefit from it beyond that, others do not.
I would try it if you have any symptoms of electrolyte imbalance,
such as muscle cramps, headaches, or fatigue.

Do I have to eat organ meats?

There is unresolved contention in the community about whether organ meats are necessary for complete nutrition on a long term (i.e. months to years) carnivorous diet.
Most other carnivory experts insist it is not necessary, and I suspect they are correct [2].
If you're losing sleep over it, a serving of liver or fish oil every now and then should cover your bases.
For the purposes of a 30 day trial, even that shouldn't be necessary.
It's simply not long enough for a deficiency to develop.

2017-12-28: I have to update this, because it's been niggling at me.
When I said I suspect they are correct, here's what I had in mind:

First, there are several compelling anecdotes of long-term carnivores who appear to be in perfect health,
and who do not eat any organs.
I have to concede that this seems stable and safe for them.

On the other hand, everything I've learned about human evolution and human brains suggests that
certain animal sourced nutrients were critical for the development of the brain on both ontogenetic and phylogentic scales.
For example, DHA is necessary in high amounts for brain functioning.
In the past, we probably got plenty of that from eating marrow and brains,
or alternatively, cold water fish.
I think a healthy diet would include these.
My point still stands, though, that this is a concern only if you continue with the diet long term,
and your needs may depend on your starting conditions.

The fact is that most low carb dieters are not eating organ meats either;
not carefully ensuring that they get plenty of DHA, for example.
If you find fault with a carnivorous diet on this basis,
and don't equally criticise a low carb diet,
that's selective enforcement of your principles.

The goal of this experiment is to remove plant foods,
to see if it improves your health, beyond the results of a ketogenic diet.
If it does improve your health, then sustainability becomes the nascent goal.
Gary Taubes devoted an entire recent article
to defending low carb diets
in the face of the fact that we can't know the long term consequences,
and that's for a diet that has substantial science behind the acute short term benefits!
If you find, as I did, that a carnivorous diet is too beneficial to give up,
then you can argue about the potential long-term detriments and how to avoid them if you choose to continue.

How do I cope in social situations and restaurants?

Don't make it a big deal.
If you think you will be uncomfortable eating this way in front of others, avoid social engagements with food,
or eat in advance.
Tell people you're testing for food sensitivities, if it makes you more comfortable.
With the exception of pizza parlours and noodle shops,
there is a plant-free solution in nearly every restaurant.
Ask for a steak or a burger patty with nothing else on the plate.
I've found that many servers respond well when you just say you eat only meat and no plants,
although some proportion will always think you said the opposite,
and many will never have considered the fact that bread and potatoes are plants.
Just politely persist.

Won't this be expensive?

Meat is more expensive than grains or legumes, but it is not more expensive than fruits and vegetables when you look at the per calorie cost.
If you get off of a prescription, or need fewer doctor visits, it's more clearly a win.
If you want to economise, choose less popular cuts, eat more pork, chicken, and ground beef.
Look for sales.
Choose fattier cuts: fat weighs less and has more energy.

Won't this be dreadfully boring?

I was worried about that, but it's turned out not to be a problem for me.
It doesn't take long for your palate to adjust to less stimulation from spices and sweeteners.
The flavour of meat starts to come out when it isn't thus drowned.
It really is delicious.

Shouldn't I be limiting protein?

Most people don't need to limit protein, because it is essentially self-limiting.
As long as you are not averse to eating fat, you are very unlikely to overeat protein in an attempt to get enough calories.
If you're worried about the depth of ketosis, see the first question.
Moreover, it turns out that most people can eat more protein than they think, and still be in ketosis.
Some can eat more than twice the minimum before ketogenesis falls below the therapeutic range.
When you eliminate all carbohydrate, your protein allowance increases.
For every gram of carbohydrate you ate on a keto diet,
you can eat two more grams of protein than you were eating before to get at most the same available glucose.
An exception worth mentioning is that people with hyperinsulinemia, typically recovering type 2 diabetics,
tend to have a higher blood sugar response and quicker reversal of ketosis in response to protein.
If this is you, or you just have a more acute response for some other reason, you may decide to moderate protein intake.
Nonetheless, it bears repeating that the benefits of a carnivorous diet do not appear to be directly dependent on ketone levels,
but on eliminating plants.